Distinct NK-cell education profiles in the same recipient after 2 HSCTs with donors of different HLA genotypes. One C1/C2 patient was diagnosed with an acute myeloid leukemia (AML-M4) in September 2002; 7 months later, she received a fully HLA-matched unrelated transplant (C1/C2 donor, transplant #14). Expectedly, CD158a and CD158b monoKIR NK cells from this patient showed similar reactivity after HSCT (left). After a leukemic relapse, she was transplanted again in March 2005, from an HLA-C–mismatched unrelated C1/C1 donor (transplant #36); thereafter, CD158a monoKIR NK cells showed hyporesponsiveness in accordance with the absence of C2 in the second donor's genotype (right).